48 research outputs found

    Prospective intra-individual comparison of standard dose versus reduced-dose thoracic CT using hybrid and pure iterative reconstruction in a follow-up cohort of pulmonary nodules—Effect of detectability of pulmonary nodules with lowering dose based on nodule size, type and body mass index

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    publisher: Elsevier articletitle: Prospective intra-individual comparison of standard dose versus reduced-dose thoracic CT using hybrid and pure iterative reconstruction in a follow-up cohort of pulmonary nodules—Effect of detectability of pulmonary nodules with lowering dose based on nodule size, type and body mass index journaltitle: European Journal of Radiology articlelink: http://dx.doi.org/10.1016/j.ejrad.2017.04.006 content_type: article copyright: © 2017 Elsevier B.V. All rights reserved

    Overcoming challenges of translating deep- learning models for glioblastoma: the ZGBM consortium

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    Objective: To report imaging protocol and scheduling variance in routine care of glioblastoma patients in order to demonstrate challenges of integrating deep-learning models in glioblastoma care pathways. Additionally, to understand the most common imaging studies and image contrasts to inform the development of potentially robust deep-learning models. Methods: MR imaging data were analysed from a random sample of five patients from the prospective cohort across five participating sites of the ZGBM consortium. Reported clinical and treatment data alongside DICOM header information were analysed to understand treatment pathway imaging schedules. Results: All sites perform all structural imaging at every stage in the pathway except for the presurgical study, where in some sites only contrast-enhanced T 1-weighted imaging is performed. Diffusion MRI is the most common non-structural imaging type, performed at every site. Conclusion: The imaging protocol and scheduling varies across the UK, making it challenging to develop machine-learning models that could perform robustly at other centres. Structural imaging is performed most consistently across all centres. Advances in knowledge: Successful translation of deep-learning models will likely be based on structural post-treatment imaging unless there is significant effort made to standardise non-structural or peri-operative imaging protocols and schedules

    A 'Performative' Social Movement: The Emergence of Collective Contentions within Collaborative Governance

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    The enmeshment of urban movements in networks of collaborative governance has been characterised as a process of co-option in which previously disruptive contentions are absorbed by regimes and reproduced in ways that do not threaten the stability of power relations. Applying a theoretical framework drawn from feminist philosopher Judith Butler this paper directs attention to the development of collective oppositional identities that remain embedded in conventional political processes. In a case study of the English tenants' movement, it investigates the potential of regulatory discourses that draw on market theories of performative voice to offer the collectivising narratives and belief in change that can generate the emotional identification of a social movement. The paper originates the concept of the ‘performative social movement’ to denote the contentious claims that continue to emerge from urban movements that otherwise appear quiescent

    New localism, old retrenchment: the Big Society, housing policy and the politics of housing reform

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    This article considers the ideology underpinning the 2010 UK Government’s welfare reform agenda in order to foreground what we see as the contradictions of new localism and the ‘Big Society’ programme as it relates to housing policy. The article has three sections. It begins by discussing some of the methodological challenges that arise in interpreting contemporary policy and the value of an historically informed approach to understand the wider ‘politics’ underpinning the ‘Big Society’ programme. To support our argument, the second part of the article traces the ‘localist’ agenda (mainly focused on England and Wales) back from the 1960s to the defeat of Labour in the 2010 general election to show how both Conservative and Labour administrations deployed localism as a justification for welfare reform and in the process created opportunities to extend the marketisation of social policy. The third section of the article considers the contemporary period, in particular reforms presented to parliament in 2011 that, if enacted, will provide new avenues for powerful interest groups to influence decisions that hitherto have been mainly the preserve of local government. The conclusion provides a summary of the key policy implications and theoretical issues that arise from the analysis

    Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa

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    Groundwater in sub-Saharan Africa supports livelihoods and poverty alleviation1,2, maintains vital ecosystems, and strongly influences terrestrial water and energy budgets. Yet the hydrological processes that govern groundwater recharge and sustainability—and their sensitivity to climatic variability—are poorly constrained4. Given the absence of firm observational constraints, it remains to be seen whether model-based projections of decreased water resources in dry parts of the region4 are justified. Here we show, through analysis of multidecadal groundwater hydrographs across sub-Saharan Africa, that levels of aridity dictate the predominant recharge processes, whereas local hydrogeology influences the type and sensitivity of precipitation–recharge relationships. Recharge in some humid locations varies by as little as five per cent (by coefficient of variation) across a wide range of annual precipitation values. Other regions, by contrast, show roughly linear precipitation–recharge relationships, with precipitation thresholds (of roughly ten millimetres or less per day) governing the initiation of recharge. These thresholds tend to rise as aridity increases, and recharge in drylands is more episodic and increasingly dominated by focused recharge through losses from ephemeral overland flows. Extreme annual recharge is commonly associated with intense rainfall and flooding events, themselves often driven by large-scale climate controls. Intense precipitation, even during years of lower overall precipitation, produces some of the largest years of recharge in some dry subtropical locations. Our results therefore challenge the ‘high certainty’ consensus regarding decreasing water resources in such regions of sub-Saharan Africa. The potential resilience of groundwater to climate variability in many areas that is revealed by these precipitation–recharge relationships is essential for informing reliable predictions of climate-change impacts and adaptation strategies
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